Automatic fire alarm



April 1930. P. F. DODUNSKI AUTOMATIC FIRE ALARM Filed July 9, 1927 Patented Apr. 22, 1930 PETER F. DODUNSKI, F SOLON, OHIO AUTOMATIC FIRE ALARM Application filed July 9,

There has been a long felt need in the field .of automatic fire alarm instruments for an instrument that may be readily installed in places where the installation of more elabo- 6 rate systems would not be considered. People will protect such places as residences, garages, barns and warehouses by an automatic alarm of simple and compact structure, while they would not do so if it was 10 necessary to install an expensive system.

The object of this invention is to provide an automatic fire alarm instrument .of novel construction that is compact and small in size and which may be easily'and cheaply made.

A further object of this invention is to provide a comparatively small sized fire alarm instrument, the operation of which is characterized by accuracy and efiectiveness.

With these and other objects in view, which will in part hereinafter become apparent and in part be stated, the invention comprises certain novel constructions, combinations and arrangements of parts as subsequently Specified and claimed.

For a full understanding of the invention reference is to be had to the following description and accompanying drawings in which:

.130 Figure 1 is a side perspective of the instrument.

Figure 2 is a plan view of the instrument with the cover thereof shown in cross section. Figure 3 is a side view, with the cover in cross section with parts removed. I

' \Vhile the preferred form of the invention is herein set forth, it is to be understood that it is not limited to the exact construct-ion set forth, because various modifications of 40 these details may be provided in putting the invention into practice within the purview of the appended claims. V

' An automatic fire alarm usually comprises two main parts; the alarm itself and the in- L4 strument actuating the alarm. Under most of the pevailing conditions where the alarm isfused it is found desirable to have the instrument at the scene where the fire is likely to take place while the alarm is removed therefrom. However, if it is desired, the

1927. Serial No. 204,602.

alarm may be included with the instrument. In the present embodiment of the invention the instrument 1 is'mounted on a base comprising the panel 2 and base plate 3, preferably of an insulating or non-conducting material. If it is found desirable, the alarm may also be mountedon this panel, but in the presend form only the instrument is shown. This plate is held to the panel by the screws 1, there being onev of these screws at each corner of the plate. It will be noted that this panelis cup-shaped or hollow in form to accommodate wires between it and the base plate. 'This panel carries the binding posts 5. and 6 that are used in connectingthe instrument to a circuit. Detachably secured to the panelis the cover or housing 7 for the mechanisnn This housing has the projections 8 which enter the openings 9 in'the panel and which function as snap members in securing the housing to the panel. To allow for the ready transmission of heat to the thermostat the housing is perforated on all sides, as shown at 10, permitting the air to freely circulate therethrough; The device which closes the circuit is securely fastened to the panel inside the housing by two brackets 11and12. The bracket 11 carries a thermostat, while the bracket 12 supports the contact mechanism; These brackets are secured to the panel by the bolts 13, the bracket 11 being insulated from the panel by insulation 14, while there is no insulation provided between the bracket 12 and the panel. 7 The bracket 11 carries the thermostat 15, which is of the construction of a thermostat shown in Patent No. 1,630,733, dated May 31, 1927. This thermostat comprises two flexible diaphragm compartments 16 which are joined together by the conduit 17. The diaphragms forming these compartments are of hard brass, although any other suitable material may be used. Inside of these compartments is the fluid which expands as it is heated. his needless to go further into the construction of this thermostat as it is clearly set forth in the patentabove referred to.

Actuatedby thisthermostat is the pin 18 having a rounded end. The movement of this 1 pin operates the contact mechanism for closing the electric circuit. The supporting mem ber 19 is brazed or welded to the bracket 11. This member has an opening through which the pin 18 projects. One end of the member 19 is bent to form the flange 20, while on the other end are the small side flanges 21. These side flanges 21 each have an opening therein to receive a hinge bolt 22. Hinged between these side flanges 21 and held therein b the bolt 22 are the angular arms 23 and 2 1. hese arms are formed from a strip of metal which is bent back on itself to provide an opening through which the bolt 22 passes. This bend:- ing also provides the long arm 23 and short arm 24 which form an angle. These arms are held in the desired angular relation by the bolt 25 carryin the nuts 26. These nuts clamp therebetween the bent up end of the arm 24. The nuts 26 may be adjusted to vary the angular relationship of the arms 23 and 24 for a purpose to be later described, A coil spring 27 is fastened between the flange 20 on the supporting member and the arm 24. It will be seen that this spring acts to keep the arms in the osition shownin Figure 2.

Securely astened to the" braeket l'2 by the rivets 28 is the arcuate plate 29. This plate comprises two portions, one portion being the dial 30, which indicates temperatures, and the other portion having the slot 31 therein. Movably mounted in this slot is the slide 32. This slide comprises a member 33 having an upstanding flange 34 that is clamped on the bolt 35 by the nut 36. On the flange 34 there is a non-corroding contact p'oin't 37 that cooperates with a similar point on the arm to complete the circuit.

The wiring of this instrument is very simple. As reviously mentioned, the bracket 12 is in electric Contact with the panel 2, as

the binding post 5. A wire runs from the binding post 6 which is insulated from the panel 2 to the thermostat 15. As the thermostat and binding post 6 are insulated from the panel the circuit will be completed only by the contacting of the arm 23 with the slide If it is found desirable to mount the alarm on the same panel with the instrument a slightly different hook up would have to be used.

The instrument is placed in the room or spot where it is desired to detect a fire, where it operates as follows: As the heat increases, the thermostat expands moving the pin 18 which in turn actuates the arm 23. This arm,

functions permits of its use in a Wide variety of places.

If the reading on the dial 30, designating the temperature at which the instrument sets off the alarm, should not correspond to the temperature of the surrounding air, the nuts 26 may be adjusted to vary the relation of the arms 23 and 24 so that the instrument will function properly at the desired temperature.

It will be noted that this instrument may be placed in one room and an alarm go off in another. It might be placed in a barn or warehouse and have the alarm go off at some remote point. In fact the number of places where it may be used is practically unlimited.

This instrument could be used in conneetion with other devices than the alarms. It might be employed in conjunction with any kind of fire fighting mechanism, such as a sprinkling system.

It is to be clearly understood that the term automatic fire alarm instrument, as used throughout the description and claims means an instrument that advises a person of exist ing temperature conditions. This construction is not intended to be limited in use with fire alarms as it could be employed in hospitals or laboratories to indicate, in ewer positive manner, the passing of a predetermined point by the temperature. v

In the ordinary use of the machine the insulation would be of substantially the dimensions as hereinbefore shown and described, but the instrument may be adapted for use in connection with high voltage by employin heavier and more effective insulating material. The wires bringing the current intothe instrument may be insulated in an improved manner or be housed in conduits, i desired.

Having thus described my invention what I claim as new, and desire to secure by Letters Patent of the United States, is: j

1. In an automatic fire alarm instrument, a calibrating adjustment comprising a lever bent back on itself to form an angular bell crank, means to adjust said angularity con SlSlJlII of a threaded stud secured to one arm of said bell crank and passing through an opening in the second. arm of said bell crank and adjusting nuts on said stud on opposite sides of said second arm.

2. In an automatic fire alarm instrument, a base, a bracket mounted thereon having spaced arms, a thermostat i'nounted between the arms and having a pin working in a guide on one of the arms, a contact lever pivotau supported on the last mentioned arm and hearing against the pin, and another Contact inthe line of movement of said lever.

3. In an automatic fire alarm instrument, a panel, brackets carried by said panel, it theirmostat mounted on one ofsaid brackets, and therihestat having a plunger, a reporting member on one of said brackets, said racket iao and member having a hole for the plunger to pass, said member having projections on each sideof said bracket, and angular arms carried by said supporting member to close an electric circuit, said arms being actuated by the plunger.

4. In an automatic fire alarm instrument, a panel, brackets carried by said panel, a supporting member on one of said brackets, said member having projections on each side of said bracket, one of said projections having a hinge flange an angular arm hinged to said projection, the other projection being bent out and aspring connected between said bent projection and the arm.

5. In an automatic fire alarm instrument, a panel, brackets carried by said panel, a lever having arms at an angle, one arm being shorter than the other, said short arm being more rigid than the long arm, a bolt connecting both arms, provided with lock nuts, for adjusting the long arm, a contact mechanism on the other of said brackets, and a thermostat acting upon said lever.

In testimony whereof I aflix my signature.

PETER F. DODUNSKI. 

